Surface grinding machine



Oct. 16, 1945. Q H.'A. SILVEN 87,

SURFACE GRINDING MACHINE I Filed Nov. 1, 1944 '7 sheets-sheet 1 HERBERTA. Suva.

ltwwuuea Oct. 16, 1945. 'H. A. SILVEN SURFACE GRINDING MACHINE F iledNov. 1, 1944 '1 Sheets-Sheet 2 o HERBERT A. \S/LVEN Mum Oct 1945- H. A.SILVEN 2,387,044

SURFACE GRINDING MACHINE Filed Nov. 1, 1944 7 Sheets-Sheet 3 awe/whomHERBERT A.I-SILVEN WLD-W Oct. 16, 1945. A um 2 ,387,044

SURFACE GRINDING MACHINE Filed Nov. 1, 1944 7 Sheets-Sheet 4 ZlfobHERBERT A; 5/1. VEN

' awuc/wtm 16, 1945- H. A. SILYIEN 2,387,044

SURFACE GRINDING MACHINE Filed Nov-.'1-, 1944 '7 Sheets-Sheet 5 HERBERTA. \S/LVEN Wm-wan Gamma;

Oct. 1-6, 1945. H. A. SILVEN 38 SURFACE GRINDING MACHINE Filed Nov. 1,1944 7 Sheds-Sheet 6 mmN Oct. 16, 1945.

H. A. SILVEN 2,387,044

SURFACE GRINDING MACHINE Filed Nov. 1, 1944 v 7 Sheeos-Sheet 7 HERBERTA. S/LVEN Patented a. 16, 1945 SURFACE GRINDING MACHINE Herbert A.Silven, Worcester, Mass.. m nor to Norton Company, Worcester, Man, acorporation of Massachusetts Application November 1, 1944, Serial No.561,401

16 Claims.

This invention relates to grinding machines, and more particularly to asurface grinding machine for grinding plane surfaces on a work piece.

One obiectof the invention is to provides simple and thoroughlypractical surface grinding machine for grinding predetermined planesurfaces on a work piece. Another object of the invention is to providea surface grinding machine in which a predetermined grinding cycle maybe obtained, that is, a predetermined relative longitudinal andtransverse movement between the grinding wheel and the work piece togrind a predetermined plane face on a work piece. Another object of theinvention is to provide ,a surface grinding machine having two opposedspaced grinding wheels which may be successively positioned inpredetermined positions for grinding opposed parallel plane faces on awork piece. Another object of the invention is to provide a surfacegrinding machine in which the work piece to be ground is mounted on anindexable work holder which is in turn supported on transversely andlongitudinally movable work supporting tables by means of which the workpiece may be moved through a predetermined cycle to grind apredetermined plane surface on a, portion of the work piece and the workpiece may be indexed to present a plurality of predetermined portionsfor grinding.

A further object of the invention is to provide a truing apparatushaving opposed truing tools arranged for simultaneously truing theoperative faces of two opposed grinding wheels in which the 'truingtools are maintained in a fixed position for a truing apparatus so thatit is not necessary to'reset the wheel positioning mechanism after atruing operation has been performed. Other objects will be apparent fromthe foregoing disclosure.

The invention accordingly consists in the features of construction,combinations "of elements, and arrangements of parts, as will beexemplified in the structure to behereinafter described, and the scopeof the application of which will be indicated in the following claims.

In the accompany n drawings, in which is.

shown one of various possible embodiments of the mechanical features ofthis invention,

Fig. 1 is a front elevation of the improved surface grinding machine;

Fig. 2 is a diagrammatic illustration of the hydraulic control andactuating mechanisms of the machine;

Fig. 5 is a fragmentary front'elevation. on

.an enlarged scale, of. the control apron, showview, on an enlargedscale, taken approximately on the line 8-9 of Fig. 8;.

Fig. 10 is a fragmentary plan view. on an enlarged scale, of thegrinding wheel truing apparatus;

Fig. 11 is alongitudinal sectional view, taken approximately on the lineli--ll of Fig. 10,

through thetruing apparatus;

Fig. 12 is a fragmentary front elevation, on an enlarged scale, of thetruing apparatus as shown in Fig. 1;

Fig. 13 is a fragmentary cross-sectional view, on an enlarged scale,taken approximately on the line I Il 3 of Fig. 10'; and

Fig. 14 is a diagrammatic illustration showing the relationship of theopposed grinding wheels and the truing tools therefor.

A grinding machine has been illustrated in the drawings comprising abase ill which-supports a longitudinally movable work table Ii onsuitable slideways (not shown). A transversely movable table I2 issupported on slideways formed on the upper surface of the longitudinallymovable table II, said slideways being arranged so that a work piecesupported on said transversely movable table may be moved eitherlongitudinally or transversely for a grinding operation.

The base In is provided with an upwardly extending column l3 whichsupports a vertically movable slide I 4 having suitable slideways formedbetween the slide l4 and the column H. The

slide i4 serves as a support for a vertically arranged grinding wheelspindle I! which in turn supports a pair of spaced grinding wheels I!and I1, the grinding wheels l6 and I1 being arranged successively togrind an upper and a lower surface on a work piece'l8. The work piece itis providedwith a plurality of webbed portions l9 having upper and lowerparallel plane surfaces to be ground to a predetermined extent.

Longitudinal table traverse The longitudinally movable table II isprovided with a hydraulically operated traversing mechanism comprising acylinder 20 which is fixed relative to the base it. A slidably mountedpiston 2i is provided in the cylinder 20 and is fixedly connected toadouble end piston rod 22 will be. readily apparent from closure thatmovement of the 4 41 toward .or-away iromr t which extends throughopposite end caps on the cylinder 28 and is fastened at its outer endsto depending brackets 23 and 24 which are fixedly mounted on the underside of opposite ends of the longitudinally movable table H. v

A control valve 25 is provided for controlling the admission to andexhaust of fluid from the cylinder 28. The valve 25 is preferably apiston type valve comprising a valve stem 28 having formed integrallytherewith valve pistons 21, 28 and 29. A manually operable cycle controllever 30 is pivotally supported on a stud 3i which is fixed relative tothe base Ill. The lever 88 is provided with a stud 32 which rides in acomparatively wide groove 83 in a spool-shaped member 38. The lower endof the lever 38 is provided with a V-shaped end portion 35 which engagesa spring-pressed roller 38. The groove 83 formed on the spool 84 is wideenough so that when the lever 38 is moved to reverse the position of thevalve 25, the lever is moved until the high point of the arrow 85 passesthe axis of the spring-pressed roller 38, after which the releasedcompression of the springpressed roller will shift the valve stem 28into its reverse position. The lever 38 serves as a cycle control leverto initiate a grinding cycle, as will be hereinafter described.

The control lever 38 is fixedly mounted on the outer end of a rock shaft3|. The inner end of the rock-shaft supports a bevel gear 31 whichmeshes with a bevel gear 31a mounted on a rotatable shaft 38. Anactuating lever 39 is mounted on the left-hand end of the shaft 88(Figs. and 8).. The lever 38 is actuated, in a manner to be hereinafterdescribed, by a dog mechanism carried by the transversely movable tablei2.

Stop and start value A manually operable stop and start valve 48 isprovided for stopping the hydraulic operation of the machine or startingthe same when desired. This valve is a piston type valve comprising avalve stem ll having formed integrally therewith valve pistons 42, 43;,45 and A8. A manually operable control lever 41 is pivotally supportedon a stud 48 which is fixed relative to the base of the machine; Thelower end of the lever 81 is provided with a. stud 48 which rides in agroove 58 formed in a spool-shaped member 5| which is fixedly mounted onthe end of the valve stem 8| ,In actual construction, as illustrated inFigs. 8 and 9, the stop and start lever 41 is operatively connected by astud "a with a slidably mounted rod l'lb. A stud 41c isflxedly mountedon the rod 41b. The stud llc rides in a cam slot 48a formed in apivotally mounted'lever 48b which is pivotally mounted at one end b isfixed relativetothe base i l. .The stud-is mounted on the opposite endof the'lever 4822. It

the foregoing disstart and stop lever he machine will be transmittedthrough the oactuate @the start stop valve 48.

Troasoerse'table traverse j v ansverselymovable slide i2 is preferabl'yaperlaited by meansiof. a'fiuid presy movable slide 1' l. ,A- piston er52 and isilxedly connected with a double end y-a stud 48c whichmechanism ,above de- I brackets 55 and 58 which are fixedly supported onthe under side of the opposite ends of the transversely movable table12.

A control valve 51 is provided for controlling the admission to andexhaust of fiuidfrom the cylinder 52. This valve is a piston type valvecomprising a valve stem 58 having iormed integrally therewith valvepistons 59, 88 and 8!. An actuating lever 82 is pivotally mounted on astud 88 which is fixed relative to the base of the machine. The lowerend of the lever 82 is provided with a narrow-pointed projection 84which engages a spring-pressed roller 85. The springpressed roller 85 isarranged to serve as a load and fire mechanism to shift the valverapidly into a reverse position. The control lever 82 is provided with astud 85 which engages a relatively wide groove 81 formed in aspool-shaped member 88 .which is fixedly mounted on the end of the valveon is fixedly-mounted relative 4 I piston rod sermon extends through theopposite end caps I ot cylinder- 52. The opposite of the con--.

i H o nec d-y n en n s:

relative tofthe base l8.- flhe l a stud 84 which rides in a groove."spool shaped member 88 which n on the end of the valve stem 18.

w r apparent irom the fore oing discl ual movement of the lever-l2 fromthe full-line tion 82a win stem 58. The relatively wide groove 81 isprovided so that the lever 82 may be moved positively until thearrow-shaped portion 84 rides over the top of the spring-pressed roller85 without moving the valve stem 58, after which the releasedcompression of the roller 85 rapidly shifts the valve 51 into itsreverse position.

The lever 52 is automatically actuated by a pair of adjustable tabledoes 88 and 880 which are adjustably mounted on the front edge of thelongitudinally movable work table H.

Grinding wheel feed' The upper end of the piston rod .12 is fixedlyconnected to a bracket 18 which is in turn fixedly mounted on-thevertically movable wheel slide H.

A hydraulically operated counterbalance mechanism is provided tocounterbalance the weight of the vertically movable wheel slide I 4 soas to facilitate movement of the same either by power or by hand. Thismechanism comprises a counter-balance cylinder 15 which'contains aslidably mounted piston 18, the slidably mounted piston 18 being fixedlyconnected to the lower end of the piston rod 12. Fluid under pressure isat all times maintained within a cylinder chamber II, the pressure ofsuch fluid being suflicient to counterbalance the weight of the wheelslide it and its associated parts.

A wheel feed control valve 11 is provided for controlling the admissionto and exhaust of fluid from the cylinder III. This valve is a pistontype v vecomprising a valve stem l8 having formed integrally therewithvalve pistons 19, 88 and 8|. A manually operable control lever 82 ispivotally supported by a stud 83 which is ever 82 supports io'rmed in ais fixedly mounted It will be readily osure that'man- Fig. 2 intoposition as indicated in' the valve 1 Mat dotted'llne posi- 0 itsreverse position. V I

W rk iadesmechanism}; In order, to facilitate grinding a work Piece.

such as thework fixedly mounted we new. w

portions or webs I to be ground, it is desirable to provide a work pieceindexing mechanism whereby after the first portion or web I8 has beenground, the work piece I8 may be precisely indexed to present the nextportion or web I8 01' the work piece I8 into operative relation with thegrinding wheels I6 and I1. The work piece I8 is preferably mounted on arotary indexing mechanism comprising an index plate 80 which is providedwith a plurality of spaced notches 8| which correspond with thenumber orportions and angular positions of the portions on the work piece III tobe ground. .A holding pawl 82 is provided for locating and holding theindex plate 80 in a predetermined grinding position. An index pawl 93 ispivotally mounted on a swinging arm 04. The pawl 03 and arm 94 arepreferably hydraulically actuated so as to facilitate a rotary indexingof the plate 90. This mechanism may comprise a hydraulic cylinder 85having a slidably mounted piston 96 which is connected to the left-handend of a piston rod 91. The right-hand end of the piston rod 81 isconnected by a stud 98 which is carried by the index pawl 93. I

An index control valve I00 is provided for controlling the indexingmovement of the work piece. This valve is a piston type valve comprisinga valve stem IOI having iormed integrally therewith valve pistons I02,I03 and I04. A manually operable control lever I is pivotally mounted ona stud I05 which is fixed relative to the base of the machine. Thecontrol lever I05 carries a stud I01 which rides in a groove I03 formedin a spool-shaped member I00 which is fixedly mounted on the right-handend of the valve stem II. It will be readily apparent that manualactuation of the lever I05 serves to control the position of the valvestem I 00. A compression spring is provided within the letthand end ofthe valve I00 (Fig. 2) normally to maintain the valve in its right-handend position.

Hydraulic, system A hydraulic system is provided for operativelyconveying fluid under pressure to and from the several mechanismshereinabove described. This system comprises a motor driven pump H0which draws fluid from a suitable source of supply such as, for example,a reservoir (not shown) formed either within or outside of the base I0,through a pipe III. The pump H0 forces fluid under pressure through apipe H2 which is connected to pass fluid under pressure through a pipeH3 into a chamber H4 formed between the valve pistons 45 and 46 in thestop and start valve 40. A pipe H5 connects the valve chamber H4 in thestop and start valve 40 with a chamber H6 formed between the valvepistons 28 and 29 in the longitudinal table control valve 25. In theposition of the valve 25 as shown in Fig. 2, fluid under pressureentering the valve chamber H6 is forced through a pipe H1 into acylinder chamber H8 formed at the right hand end of the cylinder 20 soas to move the piston 2I and the table II longitudinally toward theleft. During this movement of the table II,

fluid within a cylinder chamber H9 formed at the left-hand end of thecylinder 20 exhausts through a pipe I20, into a chamber I 2I formedbetween the pistons 21 and 28 in the valve 25,

and passes outwardly through a pipe I22.

Fluid under pressure passing through the pipe H5 from the stop and startvalve 40 also passes through a pipe I25 into a valve chamber I20 formedbetween the valve pistons 00 and GI in the transversely movable tablecontrol valve 51. In the position of the valve (Fig. 2), fluid enteringthe valve chamber I26 passes outwardly through a pipe I21 and through apipe I28 into a cylinder chamberI28 formed in the upper end of thecylinder 52 (Fig. 2) to move the piston 53 and the table l2 transverselyin a downward direction, as shown diagrammatically in Fig. 2. Durlngthis movement of the transversely movable table I2, fluid within acylinder chamber I30 formed at the lower end of the cylinder 52 exhauststhrough a pipe I3I which is connected with a valve chamber I32 in thecontrol valve 51. In the position of the valve 51 (Fig. 2) exhaust fluidentering the chamber I32 passes outwardly through a pipe I33 into a,valve chamber I34 formed in the stop and start valve 40 and retsurns tothe source of supply through a pipe I3 Fluid under pressure passingthrough the pipe H2 also enters a valve chamber I36 formed between thevalve pistons and 0| in the wheel feed control valve 11. In the positionof the valve 11 (Fig. 2), fluid under pressure entering the valvechamber I36 passes outwardly through a pipe I31 into a cylinder chamberI38 formed in the upper end of the cylinder 10 so as to cause a downwardmovement of the piston II and the wheel slide I4. During the downwardmovement of the piston 1 I, fluid within a cylinder chamber I39 exhauststhrough a pipe I40 which is connected with a valve chamber MI formedbetween the valve pistons 19 and B0 in the control valve 11 and passesoutwardly through an exhaust pipe I42 into the source of supply orreservoir.

Fluid under pressure within the pipe H2 also passes into a valve chamberI43 formed between the valve pistons I02 and I03 in the work indexcontrol valve I00. Fluid entering the valve chamber I43 passes outthrough a pipe I44 into a cylinder chamber I45 formed at the left-handend of the cylinder to cause the piston 86 to move toward the left (Fig.2) into an inoperative position. During movement of the piston 95 towardthe left, fluid within a chamber formed at Slow down valve It isdesirable to provide a suitable control for fluid exhausting from thelongitudinal table cylinder 20 so that the movement of the table may bereadily controlled. A slow-down valve I48 is provided which is a pistontype control valve having a valve stem I49. The valve stem I49 isoperatively connected with a roller I50 which is arranged to be actuatedby a pair of table dogs I5I and I52. The dogs I5I and I52 are adjustablysupported on the front edge of the longitudinally movable table I I. Inthe position'of the valve I48 (Fig. 2), fluid exhausting from thecylinder chamber H9 passes through the valve chamber I2I in the tablecontrol valve 25 and exhausts through the pipe I22 into a valve chamberI53 in the slow-down valve I48 and passes outwardly through a pipe I54into the exhaust pipe I33. In this position of the valve (Fig. 2),substantially unrestricted exhaust of fluid is permitted so as toproduce a comparatively rapid longitudinal movement of the table II. Asthe table moves to bring the web I! of the work piece I into ,operativegrindingrelationship with the grinding wheels I6 and I1, a cam face I55on the dog I5 I depresses the roller I50 which in turn moves the valvestem I 49 downwardly (Fig. 2) so as to cut off the exhaust of fluidthrough the pipe I54 and to permit fluid to exhaust through a pipe I56anda throttle valve I51 so as to slow down the traversing movement ofthe table II to a grinding speed. By adjusting the throttle valve I51,the grinding feed of the work relative to the wheel may be adjusted asdesired.

When the control valve 25 is shifted into its reverse position to causethe table II to move toward the left after the work piece has beentraversed transversely relative to the grinding wheel, it is desirablethat the initial movement of the table H toward the left he maintainedat a slow grinding speed until the work piece I 8 has traversed out ofengagement with the grinding wheels I6 or I1. In the reverse position ofthe valve 25, fluid exhausting from the table cylinder chamber II8passes through the pipe H1, the valve chamber II 6, and out through apipe I58 and through a throttle valve I59 into the exhaust pipe I33. Byregulation of the throttle valve I59, the grinding traverse of the tableII toward the left (Figs. 1 and 2) may be regulated to correspond withthe movement of the table I I in the opposite direction. When the workpiece I8 moves out of operative contact with the grinding wheels I6 orI1 as the table II moves toward the left, the cam face I55 of the dogI5i allows the roller I50 to move upwardly under the released com-Dression of a compression spring located adjacent to the top of thevalve I 48, thus allowing the valve I46 to return to the positionillustrated in Fig. 2 so that substantially unrestricted exhaust offluid may be obtained by passing the exhaust fluid through a valvechamber I60 and out through a pipe I6I which connects with exhaust pipeI33.

The dog I 5| is formed with a flat lower surface I55a which ispositioned to hold the valve I40 in a downward position (Fig. 2) so thatfluid exhausts at a relatively slow rate through the throttle valve 151.When the table II approaches the end of its stroke toward the right(Fig. 2) just before the sleeve I91 engages the end cap at the left-handend of the cylinder 20, it is desirable to cut oil the exhaust of fluidfrom the cylinder so that the fluid serves as a cushion to preventshocks and vibrations as the table II is stopped. This is preferablyaccomplished by providing a portion I 55b on the dog I5I so that as thefeeding movement is stopped, the roller I50 is per-.

mitted to rise a suflicient distance so as to cut oil exhaust of fluidthrough the pipe I56, thus stopping the entire exhaust of fluid from thecylinder 20 at the time the sleeve I91 reaches a stopped position.

The slow down valve 148 and associated parts is shown diagrammaticallyin Fig. 2. In actual construction, as illustrated in Fig. 5, the rollerI50 is rotatably supported at the upper end of a slidably mounted rod2". Thelower end of the rod 21I is connected by a stud 212 with an arm213 of a bell crank lever 214. The bell crank lever 214 is pivotallysupported on a rock shaft 215. A downwardly extending arm 216 of thebell crank lever 214 is connected by a stud 211 with a spool-shapedmember 218 which is mounted on the valve stem I49 of the slow down valve146. A manually operable lever MI is fixedly mounted on the outer end ofthe rock shaft 216.

aaeam Relief valve An adjustable pressure relief valve I64 is arrangedin the pipe line III to facilitate maintaining the desired operatingpressure within the hydraulic mechanisms above described. After thepressure within the system reaches the pressure set by the valve I64,the valve opens and allows excess fluid under pressure to pass throughthe pipe I65 into the cylinder chamber 11 to act upon the piston 16 andthus counterbalance the weight of the wheel slide I4. In order toregulate the pressure utilized for counterbalancing, fluid within thecylinder chamber 11 is connected by a pipe I66 with a second adjustablepressure relief valve I61. By regulating the valve I61, the desiredcounterbalance ressure may be secured within the chamber 11 so as tocounterbalance the weight of the slide l4 and its associated parts.Excess fluid under pressure within the counterbalance cylinder 15 willopen the valve I61 and allow the excess fluid under pressure to exhaustthrough a pipe I68 into the reservoir.

As shown diagrammatically in Fig. 2, the counterbalance cylinder 15appears to be the same diameter as the feed cylinder 10 but in actualpractice the counterbalance cylinder 15 is considerably larger indiameter so as to provide a large Piston area for the counterbalancingoperation. In order to compensate for quick vertical motion of the feedpiston 1| so that the chamber 11 will always be maintained full of oilon the up stroke, a check valve I69 is connected in the pipe line I66. Apipe leads from the check valve I69 into the reservoir. If there is anytendency to create a vacuum within the cylinder chamber 11, due to rapidmovement of the wheel slide I4, fluid is sucked up through the pipe andthe check valve I69 into the cylinder chamber 11 to maintain the chamber11 filled at all times.

Hand traverse-longitudinal table front of the machine base. The handwheel I10 is connected through a clutch mechanism comprising a slidablymounted clutch member III (shown diagrammatically in.Fig. 2) and aclutch member 112 which is mounted on one end of a rotatable shaft I13.The shaft I13 also supports a gear or pinion I14 which meshes with arack bar (not shown) which is fixedly supported on the under side of thetable II. A compression spring I15 serves normally to hold .the clutchmember I H in engagement with the clutch member I12.

During hydraulic operation 01' the table, it is desirable that theclutch be disconnected so that the hand wheel I10 will not turn duringthe power traversing movement of the table II. This is preferablyaccomplished by a hydraulically operated mechanism. Fluid pressureentering the valve chamber I I4 of the stop and start valve I40, in theposition of the valve shown in Fig. 2, passes out through a pipe I16.into a cylinder chamber I-11 to move the clutch member I1I downwardly(Fig. 2) against the compression of the spring I15 to maintain the handwheel I10 disengaged while the hydraulic operating mechanisms areoperative.

machine and render the manual traverse mecha- Hand traverse-transversetable A similar manually operable traverse mechanism is provided tofacilitate manual adjustment of the transversely movable table I2. Thismechanism may comprise a manually operable rotatably mounted hand wheelI80 which is rotatably supported in fixed relation with thelongitudinally movable table II. The hand wheel I80 is mounted on theouter end of a rotatable shaft III. The inner end of the shaft I8Isupports a clutch member I82 which is normally maintained in engagementwith a clutch member I83 by means of a compression spring I84. Theclutch member I83 is fixedly mounted on the lower end of a rotatableshaft I85. The'other end of the shaft I85 is provided with. a gear orpinion I88 nisms operative, the pipes I84 and I95 will be connectedthrough the valve chamber I98 so that fluid may readily by-pass betweenthe opposite end chambers H8 and .I I9 of the cylinder 20. In thisposition of the parts, the table II may be readily which meshes with arack bar (not shown) to move the transversely movable table I2 relativeto the longitudinally movable table I I. In actual Y construction a gearmechanism is interposed between the hand wheel 80 and the clutch part82.

Since this mechanism is not considered to be a part of the presentinvention, the diagrammatic start lever 41 is moved in acounterclockwise direction to shift the valve stem 4I toward the right(Fig. 2), which movement shifts the valve piston 45 so that fluid withinthe cylinder chambers I11 and. I 88 may exhaust through pipes I18 andI81 through a valve chamber I89 located between the valve pistons 44 and45 and exhaust through a pipe I98 into the reservoir. As soon as thestop and start valve is moved into this position, the releasedcompression of the springs I15 and I84 engages the clutch parts I1I-I12and I82I83 so as to render the manually operable traverse wheels I18 andI80 operative.

During the manual traverse of the longitudinally movable table II andthe transversely movable table I2, it is desirable to provide a suitablefluid pressure by-pass so that the manual traverse may be accomplishedwithout overcoming resistance of the fluid within the hydraulic system.As shown in Fig. 2, a pipe I9I connects thepipe' I28 with a valvechamber I93 in the stop and start valve 40. A pipe I92 connects the pipeI3I with the valve chamber I93. When the stop and start lever 41 ismoved in a counterpipes above described into the chamber I30 and viceV6138.

Similarly, a by-pass is provided for the cylinder 28. A pipe I94 isconnected between the pipe H1 and a valve chamber I 98 in the stop andstart valve 40. A ipe I95 is connected between the pipe I 20 and thevalve chamber I98. When the valve 40 is shifted into its right-hand endposition to stopthe hydraulic operation of the traversed manually byrotation of the hand wheel I18.

Work table-stop mechanism It is desirable to provide suitable stops forpreon the left-hand end of the cylinder 28 which serves as a positivestop to limit the infeeding movementof-the table II.

Similarly, a stop sleeve mounted on the piston rod 54 and serves tolimit the movement of the transversely movable slide I I2 toward therear of the machine,that is, in an up direction in Fig. 2. When theslide I2 moves toward the rear to traverse the work piece relative tothe grinding wheels, this movement continues at a grinding speed untilthe sleeve I98 Wheel slide-stop mechanism As above stated, the machineis arranged for grinding an upper and a lower plane surface on webs I9projecting from a work piece I8. Opposed spaced grinding wheels I8 andI1 are provided. The wheel slide I4 is first moved downwardly to grindthe upper surface of the web I9. After all of the upper surfaces of thewebs I9 have been ground to the desired and predetermined extent, thewheel slide I4 may be moved upwardly to position the lower wheel I1 inproper position for grinding the lower surfaces of the webs I9. It isdesirable to provide suitable stop mechanisms for precisely determiningthe up and down posi-' tion of the wheel slide I4 so that the wheels I8and I1 may be precisely positioned for the grinding operation. Asillustrated in Fig. 2, the piston rod 12 is provided with a threadedportion I99 which serves as a feed screw. A sleeve 208 is screw threadedonto the feed screw I99. A

worm gear 28I is slidably keyed to the outer periphery of the sleeve288. The worm gear 20I is held against axial movement so that the pistonrod 12 and the sleeve 288 are free to move in an shown in the expiredpatent to Norton, No. 762,--v

838 dated June 14, 1904. The feed wheel is provided with a micrometeradjusting mechanism 204 and a stop (not shown) by means of which thefeed wheel 283 may be turned to a predetermined position precisely toadjust the position of the upper grinding wheel I8. The lower end of thesleeve I98 is adjustably 200; when moved downwardly, engages the end capof the cylinder 10 and serves as a positive stop to limit the downwardfeeding movement of the wheel slide I l and the grinding wheel it. Tocompensate for wear on the grinding wheel l0, it is merely necessary toadjust the hand wheel 203 to reposition the stop sleeve 200 so as toallow the wheel slide ll and the grinding wheel I to move to a slightlylower position.

A similar feeding mechanism is provided to control the upward feedingmovement of the slide N and the grinding wheel I! to position thegrinding wheel I! in a predetermined position relative to the undersurface of the web l3 on the work piece l8 to be ground. The piston rod12 is provided with a second feed screw 205. A stop sleeve 20! is screwthreaded onto the feed screw 206. A worm gear 208 surrounds the sleeve20'! and is slidably keyed to the outer periphery thereof. A worm 200meshes with the worm gear 208. A manually operable feed wheel is mountedon the outer end of the shaft supporting the worm 200. This feed wheel2|0 is provided with the usual micrometer adjusting mechanism 2 and astop (not shown) for limiting the rotary movement of the feed wheel 2|0.When the wheel slide l4 and grinding wheel H are moved in an upwarddirection, the feeding movement continues until the upper end of thesleeve 20! engages the end face of the cap enclosing the lower end ofthe cylinder which serves asa positive stop to limit the upward feedingmovement of the grinding wheel assembly precisely to position theoperative face of the grinding wheel I! relative to the lower face ofthe web I! to be ground. It will be readily apparent that by adjustmentof the hand wheel 2 I 0, the position of the stop sleeve 201 may bereadily adjusted so as to compensate for wear of the grinding wheel H.

In order to automatically shift the lever 30 in timed relation with themovement of the transversely movable table l2, 9. pair of dogs M5 and 2i6 are carried by the transversely movable slide l2. As showndiagrammatically in Fig. 2, the dogs 2I5 and HS are mounted on the stopsleeve I08. These dogs are arranged to engage an arm 2" of a bell cranklever 2l8. The bell crank lever 2"! is pivotally supported on a shaft2|9. The short arm of the bell crank 2S8 is connected by a link 220 withthe lever 30. It will be readily apparent from the foregoing disclosurethat when the transversely movable slide l2 moves transversely to apredetermined position in either direction, the bell crank lever 218will be rocked by one of the dogs 2 I5 or 216 to shift the cycle controllever 30 into a reverse position, thus shifting the control valve 25 soas to start the movement of the work table II.

In actual construction, as illustrated in Figs. 5, 6, 'l and 8. the dogsM5 and 2l5 carried ly the transversely movable table l2 serve to rockthe lever 30 to rock the shaft 38. Rotary motion oftransversely movabletable l2. The dog 2l6 is adlustably mounted on a pivotally mounted0011'? trollever 2|6a which is pivotally supported by a stud 21Gb on thedog H5. The control lever 2I6a is normally held in an operative position(Fig. 6) byjmeans of a spring 2l0c. If it is desired to traverse thetable I 2 toward the right (Fig. 6) beyond the normal stroke, the. lever2160. may be moved in a clockwise direction to raise the dog 2|6 to aninoperative position out of the path of the stud 2" on the lever 39.

' Interlock-work index It is desirable to provide a suitable interlockto prevent indexing of the work piece It when the work piece is in anoperative position relative to the grinding wheels l6 and II. Thisinterlock preferably comprises an adjustable dog 225 which is adjustablymounted on the front edge of the longitudinally movable table II. Thedog 225 is provided with a lower plane surface 226. The lever I05 isprovided with a roller 22'! which is positioned so that when the leverI05 is in an inoperative position. the roller l2! will ride beneath thesurface 226 of the dog 225. When the roller 22'! is positioned beneaththe surface 226, it serves as a stop to prevent shifting of the indexcontrol lever in a counterclockwise direction so as to preventinitiating an indexing movement of the work piece l8 except when thetable II is in an extreme left-hand end or loading position. When thetable I I is moved to its left-hand end or loading position, the dog 225moves out of the path of the roller 22'! so that the lever I05 may bereadily shifted in a counterclockwise direction to index the work piecein the manner above described.

Truiny apparatus It is desirable that a suitable truing apparatus beprovided so that the opposed faces of the grinding wheels l6 and I? maybe simultaneously trued to the desired and predetermined extent. It isdesirable to provide a truing mechanism in which the truing diamonds arefixed during the normal operation of the machine so that after thewheels have been trued, it is not necessary to reset the feedingmechanism before resuming the grinding operation. The diamonds areadjustable only to compensate for wear of the diamond itself. In thegrinding operation illustrated in the present case, it is desirable tohave the operative faces of the grinding wheels back tapered toward thecenter in a manner such as that diagrammatically shown in Fig. 14. A

pair of truing tools or diamonds 230 and 23l are provided to true theoperative faces of the grinding wheels l6 and I1, respectively. Thesediamonds are mounted in a manner to be herein after described and arearranged to traverse in a direction such as illustrated by the line 232in the diagrammatic illustration in Fig. 14. This line 232 is parallelto the face of the wheel IE to be trued by the diamond 230 and is alsoparallel to the face of thegrinding wheel I! to be trued by the diamond23].

This truing mechanism has been illustrated in Figs. 11, 12, 13 and 14. Aframe 234 is fastened to the column l3 of the machine. This frame 234serves as a, support for a plate 235. The plate 235 is arranged to pivoton a stud 235 and may be clamped in adjusted position on the frame 234bymeans of clamping screws 23'! and 238. The clamping screws 23'! and238 pass through elongated slots 233 and 240 formed in the plate 235. Itwill be readily apparent from the foregoing disclosure that the plate235 which serves as a support for the truing apparatus may be angularlyadjusted to determine the path of movement of the truing tools 230 and23!.

The plate 235 is provided with a pair of spaced bearing brackets 2 and242. The bearing bracket 24I rotatably supports a longitudinallyextending sleeve 243 (Fig. 12). is rotatably supported'within a sleeve244 which is journalled in a bearing surface formed in the bracket 242.The sleeve 243 is provided with an adjustabiy mounted truing tool arm245 which serves as a support for the truing tool 23I. The sleeve 244 isprovided with a truing tool arm 248 which serves as a support for thetruing tool 238.

In order to traverse the truing tools 238 and 23I across the operativefaces of the grinding wheels I8 and II respectively, a suitable traversemechanism is provided comprising a hand wheel 241 which is mounted onthe outer end of a feed screw shaft 248 having a feed screw 249 formedat its left-hand end (Fig. 11). The feed screw The sleeve 243 justingknob 288 isprovided for adjusting the arm 252.

when it is desired to true the grinding wheels. the operator adjusts theposition of the feed stop control wheels 283 and 2I8, respectively, byan amount equal to the amount it is desired to true off the faces of thegrinding wheels. After this adjustment has been made, the hand wheel 241is rotated to traverse the truing tools 238 and 23I across the operativefaces of the grinding wheels I8 and II, respectively, to true theoperative faces thereof. The diamonds 238 and 23I are not ad- 249 isscrew threaded into a nut 258- which is fixedly mounted relative to theplate 235 and the bracket 24I. It will be readily apparent from theforegoing disclosure that rotary motion of the hand wheel-24'! will beimparted through the feed screw 249 and the nut 258 to traverse thesleeves 243 and 244 longitudinally relative to the plate 235 so as toimpart a traversing movement to the truing tools 238 and 23I to traversethe same across the operative faces of the grinding wheels I8 and II,respectively.

In order to facilitate adjustment of the truing tools 238 and 23! tocompensate for diamond wear, an arm 25I is fixedly mounted on therighthand end of the sleeve 243. An arm 252 is fixedly mounted on theright-hand end of the sleeve 244.

The arms 25I and 252 are substantially identical in shape and arearranged to facilitate angular adjustment of the sleeves 243 and 244,re-

ju'sted during use of the machine except to compensate for wear on thediamonds themselves.

A one-shot lubricant pump 285 (Fig. 2) is provided to convey lubricantto thewheel slldeway and to the work table ways. A manually operableknob 288 is provided for manually actuating the one-shot pump 285 whendesired. If desired, the one-shot pump 285 may be actuated in timedrelation with the operating mechanisms of the machine. As ,illustratedin the drawings. the pump 285 is actuated in timed relationship'with thework indexing mechanism so as automatically to convey a shot oflubricant through a pipe 292 and through pipes 293 and 294 to the wheelslide and work table ways respectively (as illustrated diagrammaticallyin Fig. 2) each time the work index mechanism is actuated. A pipe 281 isconnected at one end with the pipe I48. The other end of the pipe 281 isconnected to conveyfluid under pressure to a cylinder chamber 288 in acylinder 289. A piston 298 is slidably mounted in the cylinder 289 andis formed integral with ing screw 258 to facilitate manual-adjustmentthereof. The screw 258 passes through an apercollar 28I is mounted onthe screw 258 and bears against a plane surface milled on the side ofthe rod 253. A thrust collar 282 is slidably mounted on the outer end ofthe adjusting screw 258 to facilitate manual adjustment thereof. Acompression spring 283 is interposed between the thrust collar 282 andthe left-hand inner face of the aperture 254 of the arm 25I. It will bereadily apparent from the foregoing disclosure that a rotary adjustmentof the knob 259 will be transmitted. angularly to adjust the arm 25Irelative to the fixed rod 253 to adjust the position of the diamond 23Iwhich trues the lower wheel Il. The knob 259 is provided withgraduations 284 and an index mark 285 is fixedly mounted on the arm 25Ito-facilitate precise adjustment of the diamond 23I in setting up themachine and also to compensate for wear of the diamond 23I.

A similar adjusting screw (not shown) is provided for adjusting the arm252 relative to the fixed rod 253. The details of this adjustment havenot been illustrated since this mechanism is identical with that shownin connection with the arm '25I above described. A graduated ada stem29I which connects the knob 288 with the one-shot pump 285. It will bereadily' apparent from the foregoing description that when the lever.I85 is shifted to actuate the control valve ing machine will be readilyapparent from the foregoing disclosure. Assuming all of the parts havebeen previously adjusted for grinding a plurality of webs I8 on a workpiece I8, the work piece I8 is placed in position on the work holderwhich is carried by the transversely movable table I2 and is clamped inposition thereon by means of a clamping nut 218. The stop and startlever41 is then shifted into the position illustrated in Fig. 2 to render themanual traverse wheels "8 and I88 inoperative and to render'th'ehydraulic system operative. lever 38 may then be shifted in a clockwisedirection to initiate a grinding cycle. This movement of the cyclecontrol level 38 shifts the valve 25 toward the right (Fig. 2) to passfluid under pressure into the cylinder chamber II9 to cause the table II to move longitudinally toward'the right so as to feed the work pieceinto grindingrelation with the grinding wheel I8. This movement of thework table II continues until the work piece moves so that the grindingwheel I 8 is positioned as shown diagrammatically in Fig. 7 in position"in. When the work piece approaches this position. the table dogI5I,'through the roller I58, closes the slow-down valve I48 to slow downthe feeding movement of the table II. At the The cycle control sametime, the table dog 69 engages and shifts the control lever 62 in aclockwise direction to shift the valve 51 toward the right. The tablemovement serves to shift the lever 62 until the arrow point 64passes-the high point on the roller 65, after which the releasedcompression of the spring-pressed roller 65 quickly throws the valve 51into the reverse position. By this time the stop sleeve I91 has engagedthe fixed stop, that is, the end cap on the left-hand end of thecylinder 20 which limits the longitudinal movement of the table H towardthe right.

when the valve assumes its right-hand end position, fluid under pressureis passed through pipe I3I into cylinder chamber I30 to start themovement of the transversely movable table I2 toward the rear of themachine so as to traverse the web I9 transversely relative to thegrinding wheel I6 to grind the upper plane surface of the web I9 to thedesired and predetermined extent. This grinding stroke continues untilthe stop sleeve I98 engages the cylinder cap at the lower end of thecylinder 52 (Fig, 2) which positively limits the transverse grindingfeed. As the table 52 reaches the rearward end of its stroke, the dog2I5 carried by the table I2 engages the arm 2H and rocks the bell cranklever 2 I8 in a counterclockwise direction, which movement servesthrough the link 220 to shift the cycle control lever 30 in acounterclockwise direction into the position shown in Fig. 2 so thatfluid under pressure will pass through the pipe II'I into the cylinderchamber H8 of the cylinder 26 to start the table II moving in adirection toward the left (Fig. 2). The transverse movement of the slideI2 toward the rear is a relatively slow movement due to the fact thatfluid exhausts from the cylinder chamber I29 through the needle valveI68 which controls the rate of movement thereof.

As the table II starts its movement toward the left, it is desirablethat the initial movement thereof, until the work has moved clear of thegrinding wheel I6, be at a slow grinding speed. This is preferablyaccomplished by allowing the fluid exhausting through the pipe I20 topass through the throttle valve L57, as previously described, to producea slow grinding feed of the table II toward the left. After the rollerI5I rides oi! the lower flat face I550 of the'dog I5I, the releasedcompression of the spring will shift the slow-down valve I48 upwardlyinto the position shown in Fig. 2, after which fluid may exhaust at asubstantially unrestricted rate through pipe I54 instead of through thethrottle valve I51 so that the table II moves at a rapid rate durin theremainder of its longitudinal'movement toward the left. The table movestoward the left until the dog I52 again depresses the roller I50which-serves again to close the slow-down valve 8, thuscutting oi!exhaust of fluid from the cylinder to stop the table at its left-handend position. At the same time, the dog 69a engages the lever 62 androcks it into the position illustrated in Fig. 2 to shift the valve 51into its extreme left-hand end position so that fluid under pressurewill pass through pipes I21 and I28 into cylinder chamber I29 to movethe table I2 transversely toward the front of the machine at a rapidrate so that the work piece returns to its initial or starting position,thus completing a grinding cycle. After the completion of a cycle, theposition of the grinding wheel may be ad- Justed if desired. Thegrinding cycle may continue to be repeated automatically untilinterrupted manually in a manner to be hereinafter described.

When it is desired to interrupt the grinding cycle, after the workpiece'has repeated the desired number of cycles as above described, atrip lever 280 (Fig. 2) is provided which serves to swing the dog 2I6out of the path of the arm 2" of the bell crank lever 2I8 so that thetable II may move to its extreme forward position. The lever 28I maythen be actuated to open the slow down valve I48 to allow unrestrictedexhaust of fluid from the cylinder 20 so that the table II will traverserapidly toward the left to a loading position. In this position, theindex control lever I05 may be shifted in a counterclockwise directionto index the work piece I8 through ninety degrees to present the nextweb IS in operative relation for a grinding operation. The grindingcycle may then be continued on successive webs until the upper planesurfaces have all been ground to the desired and predetermined extent.After the lever 280 has been tripped to render the dog 2I6 inoperative,a lever 28I is also moved in a clockwise direction to raise the valvestem I49 so that fluid may pass through to the cylinder 20 to cause arapid movement of the table II into its loading position.

When it is desired to adjust the position of the wheels I 6 and I1, thatis, the stop position thereof, to compensate for wheel wear or for atrulng operation, it is merely necessary for the operator manually toadjust the hand wheels 203, and 2III, respectively. If these adjustmentsare made for a truing operation, the truing tools may be traversedlongitudinally by a rotary motion of the hand wheel 24! to transmit atraversing movement of the diamonds 230 and 23I so as to traverse themacross the operative faces of the grinding wheels I6 and II,respectively.

It will thus be seen that there has been provided by this inventionapparatus in which the various objects hereinabove set forth togetherwith many thoroughly practical advantages are successfully achieved. Asmany possible embodiments may be made of the above invention and as manychanges might be made in the embodiment above set forth, it is to beunderstood that all matter hereinbefore set forth or shown in theaccompanying drawings is to be interpreted as illustrative and not in alimiting sense.

I claim:

1. In a grinding machine having a base, a wheel slide thereon, arotatable spindle on said slide, a pair of spaced grinding wheels onsaid spindle having opposed operative faces which are arrangedsuccessively to grind opposed plane faces on a work piece, meansincluding a piston and cylinder to move said slide successively toposition the grinding wheel faces in operative positions, and a pair ofindependent micrometer adjusting mechanisms to limit the movement ofsaid slide in either direction precisely to locate the wheel facesrelative to the work piece.

2. In a grinding machine having a base, a wheel slide thereon, arotatable spindle on said slide, a pair of spaced grinding wheels onsaid spindle having opposed operative faces which are arranged to grindopposed plane faces on a work piece, means including a piston andcylinder to move said slide, a double end piston rod connected with saidpiston, connections between said rod and said slide, a pair of stopsleeves which are screw threaded on the piston rod at opposite ends ofsaid cylinder which are arranged to engage the ends of said cylinder soas to limit ass'mu 9 I the movement of said piston and wheel slide ineither direction, and an independent micrometer adjusting mechanismprecisely to adjust each of i said sleeves relative to said piston rodto facilitate positioning the operative faces of the grinding wheelssuccessively to grind opposed plane faces on a work piece.

3. In a grinding machine having a vertically movable grinding wheelslide, a rotatable grinding wheel thereon, a 'piston and cylinder tomove said slide, a piston rod connecting said piston with said slide, anadjustable stop for limiting the movement of said piston in onedirection, a micrometer feed mechanism for adjusting said stop, acontrol valve therefor, a longitudinally:

movable table, a transversely movable table on said longitudinallymovable table, a piston and cylinder for said transversely movabletable, a

control valve therefor, and an automatic cycle control mechanism tocause a transverse movement of said table to a predetermined positionand a return thereof to its initial position so as to grind apredetermined plane face on a work piece.

4. In a grinding machine having avertically support on said transverselymovable table which is arranged successively to present predeterminedportions on a work piece for a grinding operation, and an automaticcycle control mechanism for said valves to cause a movementof saidlongitudinally movable table to a predetermined position, then amovement of said transversely movable tableto a predeterminedposition soas to grind a predetermined plane face on a work piece, after which saidtables are moved to their initial positions.

7. In a grinding machine having a vertically movable grinding wheelslide, a pair of spaced rotatable grinding wheels on said slide havingopposed operative faces which are arranged to grind opposed plane faceson a work piece, a

piston and cylinder to move said slide, a piston rod connecting saidpiston with said slide, a pair of adjustable stop sleeves on said pistonrod successively to position the operative faces of said grindingwheels, a control valve therefor, a longitudinally movable table, apiston and cylinder to move said table, a control valve therefor,

Y a transversely movable table on said longitudimovable grinding wheelslide, a rotatable wheel thereon, a piston and cylinder to move saidslide, a piston rod connecting said piston with said slide, anadjustable stop for limiting the movement of the piston in onedirection. a micrometer feed mechanism for adjusting said stcp,,acontrol valve therefor, a longitudinally movable ta- .ble, a piston andcylinder to move said table,

a control valve therefor, a transversely movable table on saidlongitudinally movable table, a piston and cylinder to move saidtransversely movable table, a control valve therefor. a rotatableindexable work support on said transversely movable table, and anautomatic cycle control mechanism for said valves for causing a movementof said longitudinally movable table to a predetermined position, then amovement of said transversely movable table to a predetermined positionso as to grind a predetermined plane faceon a work piece.

5. In a grinding machine as claimed in claim 4. thecombination with theparts and features therein specified, of a counterbalance piston andcylinder, said counterbalance piston being connected to the wheel slidepiston rod, a fluid pressure system including a fluid pump, anadjustable relief valve in said system to maintain a predeterminedoperating pressure in said system, a pipe to convey fluid exhaustingfrom said relief valve into said counterbalance cylinder, and

a relief valve associated with the counterbalance cylinder to facilitatecontrolling the pressure in said latter cylinder so as to counterbalancethe weight of the wheel slide and associated parts.

6. In a grinding machine having a vertically tudinally movable table, apiston and cylinderto move said transversely movable table, a controlvalve therefor, a rotatable indexable work nally movable table, a pistonand cylinder to move said transversely movable table, a control valvetherefor, a rotatable indexable work'support on said transverselymovable table which is arranged successively to present predeterminedportions on a work piece for a grinding operation, and an automaticcycle control mechanism for said valves to cause a movement of saidlongitudinally movable table to a predetermined position, then amovement of said transversely movable table to a predetermined positionso as to grind a, predetermined plane face on a work piece, after whichsaid tables are moved to their initial positions, said control mechanismbeing arranged so that the cycle of operation repeats itself until thesurface of the work piece has been ground to the desired andpredetermined extent. 8. In a grinding machine having a verticallymovable grinding wheel slide, a pair of spaced grinding wheels thereon,a piston and cylinder to move said slide, a control valve therefor, alongitudinally movable table, a piston and cylin-- der to move saidtable, a control valve therefor, a manually operable control levertherefor, a transversely movable table on said longitudinally movabletable, a piston and cylinder to move said transversely movable table. acontrol valve therefor, a control level-for said latter valve, ad-

, :Iustable dogs on said transversely movable table predeterminedposition, after which the transversely movable table movestransversely'to' a predetermined position to grind a plane face on thework piece and thereafter successively to return said longitudinallymovable table and said transversely movable table to, their initialpositions.

9. In a grinding machine as claimed in claim 8,. the combination withthe parts and features therein specified, 'of a. manually operablelever,

and connections between said lever andone of the dogs on saidtransversely movable table to render said dog inoperative and thereby tointerrupt the continuous cycle.

vl0. In a grinding machine as claimed in claim 8, the combination withthe parts and features therein specified, of a manually operable leverwhich is operatively connected to render one of the transverselymovable'table dogs inoperative so as to interrupt the continuousgrinding cycle, and a second manually operable .lever which isoperatively connected to shift said tables to a loading position after apredetermined grinding operation has been completed.

11. In a grinding machine having a vertically movable grinding wheelslide, a pair of spaced grinding wheels thereon, a piston and cylinderto move said slide, a control valve therefor, a longitudinally movabletable, a. piston and cylinder to move said table, a control valvetherefor, a manually operable control lever therefor, a transverselymovable table on said longitudinally movable table, a piston andcylinder to move said transversely movable table, a control valvetherefor, a control lever for said latter valve, adiustable dogs on saidtransversely movable table to actuate the control lever for saidlongitudinally movable table, and adjustable dogs on said longitudinallymovable table to actuate the control lever for said transversely movabletable, said dogs and levers being arranged automatically to traverse thelongitudinally movable table to feed the work toward the -grinding wheelto grind a plane surface on a work piece to a predetermined extent,after which the transversely movable table is automatically traversedtransversely relative to the grinding wheel to traverse the grindingwheel across a predetermined face on the work piece, thereafterautomatically to traverse the longitudinally movable table to move thework piece to an inoperative position first at a. grinding rate untilthe work is out of grinding contact with the grinding wheel, after whichthe longitudinally movable table moves rapidly to a predeterminedposition and thereafter automatically to traverse the transverselymovable table rapidly to return the work piece to its initial position.

12. In a grinding machine having a vertically movable grinding wheelslide, a pair of spaced grinding wheels thereon, a piston and cylinderto move said slide. a control valve therefor. a longitudinally movabletable, a piston and cylinder to move said table, a control valvetherefor, a manually operable control lever therefor, a transverselymovable table on said longitudinally movable table, a piston andcylinder to move said transversely movable table, a. control valvetherefor. a control lever for said latter valve, adjustable dogs on saidtransversely movable table to actuate the control lever for saidlongitud naliy movable table, and adjustable do s on said lon itudinallymovable table to actuate the control lever for said transversely movabletable, said dogs and levers being arranged automatically to traverse thelongitudinally movable table to feed the work toward the grinding wheelat a grinding rate to grind a plane surface on a work piece to apredetermined extent, after which the transversely movable table isautomatically traversed transversely relative to the grinding piece toan inoperative position first at-a grinding rate until the work is outof grinding contact with the grinding wheel, after which thelongitudinally movable table moves rapidly to a pre-. determinedposition and thereafter automatically to traverse the transverselymovable table rapidly to return the work piece to its initial position.

13. In a grinding machine as claimed in claim 4, the combination withthe parts and features therein specified, of a work index mechanismincluding an index plate, a holding pawl to locate said plate and workpiece in a predetermined position for a grinding operation, a. pivotallymounted actuating pawl associated with said indexing plate, a piston andcylinder to actuate said latter pawlto index said work piecesuccessively to present predetermined portions of the work piece intogrinding positions, a control valve therefor, a manually operablecontrol lever to actuate said valve, and an interlock to preventmovement of said control lever except when the work table is in aninoperative or loading position.

14. In a grinding machine as claimed in claim 4, the combination withthe parts and features therein specified, of a work indexing mechanismincluding an index plate, a holding pawl to locate said plate and workpiece in a predetermined position for grinding, a pivotally mountedactuating pawl associated with said index plate, a piston and cylinderto actuate said latter pawl to index said work piece successively topresent predetermined portions of the work piece into grindingpositions, a control valve therefor, a manually operable control leverto actuate said valve, and an interlock including anadjustable dog onsaid longitudinally movable table to prevent movement of said controllever to initiate an indexing movement of the work piece except when thelongitudinally movable table is in an inoperative or loading position.

15. In agrinding machine as claimed in claim 4, the combination with theparts and features therein specified, of a lubricating system for thewheel slide and work table ways, including a oneshot lubricant pump,manual means to actuate said pump, a piston and cylinder to actuate saidpump, operative connections between said work index control valve andsaid cylinder whereby fluid under pressure is admitted simultaneously tothe work index cylinder and to the lubricant pump cylinder to actuatesaid lubricant pump each time the work indexing mechanism is actuated toconvey lubricant to the wheel slide and table ways.

16. In a grinding machine as claimed in claim 4, the combination withthe parts and features therein specified, of a slow-down valve in thewheel at a grinding rate to allow the grinding wheel to grind apredeterm ned face on the work piece, thereafter automatically totraverse the longitudinally movable table to move the work exhaust sideof said longitudinally movable table cylinder, said valve normally beingpositioned to allow substantially unrestricted exhaust of fluid fromeither end of said table cylinder, said valve in a second position beingarranged to reduce the exhaust of fluid from one end of the cylinder soas to change the rate of movement of said table from a rapid approachingto a grinding feed, and means including an adjustable dog on saidlongitudinally movable table to actuate said valve as the work pieceapproaches operative engagement with the grinding wheel to change therate of movement of the table to a grinding speed.

HERBERT A. SILVER.

